IB Bilgy HL Tpic Guide 4.2 & 10.1 Meisis Name Per. 1. Define hmlgus chrmsmes. 2. Explain reductin divisin. 3. State the functin f meisis. 4. Add chrmsmes and anntate the diagram belw summarizing the steps in meisis. Identify the stage where crssing ver ccurs and state its effect. 5. Cmpare mitsis and meisis: Number f divisins Number f daughter cells Chrmsme number in daughter cells Functins: Mitsis Meisis 1
6. Outline the majr events and mvements f chrmsmes ccurring at these stages f meisis: Meisis I Meisis II Interphase Interphase N replicatin ccurs in interphase between Meisis I and II. Prphase I Prphase II Metaphase I Metaphase II Anaphase I Anaphase II Telphase I Telphase II Cytkinesis Cytkinesis 7. Deduce the answers t these questins. a. A cell with a diplid number f 12 chrmsmes meisis. Hw many daughter cells will be prduced and with hw many chrmsmes in each? Cells: Chrmsmes: b. A gamete cntains 18 chrmsmes. Hw many chrmsmes in the smatic cell? Chrmsmes: c. A diplid cell with 16 chrmsmes underges meisis. Hw many chrmatids are present in metaphase I? Chrmatids: 2
8. A cell with a chrmsme number (n) f 3 underges meisis. Draw a series f diagrams t utline the steps f meisis. 9. Describe what yu can see in this image. 10. Distinguish between chrmsmes, sister chrmatids and bivalents. 3
11. State during which stage f meisis is the image in Q8 mst likely t be seen. 12. Outline the prcess f crssing ver and anntate the diagram. Synapsis Chiasma frmatin Separatin 13. State the effect f crssing ver in terms f genetic diversity. 14. A diplid cell carries genes A and B. There are dminant and recessive alleles fr these genes. The cell is heterzygus fr bth genes. a. What cmbinatin f gametes culd be prduced if there was n crssing ver? AB r b. What cmbinatins f gametes culd be prduced if a chiasma frmed between the lci f genes A and B? 15. Outline hw randm rientatin in metaphase I leads t further genetic variatin. State the number f rientatins pssible in human cells. 4
16. Mendel made many advances in genetics thrugh careful bservatin and statistical analysis. a. State Mendel s Law f Independent Assrtment b. What assumptin is made here? There is n c. Explain the link between the law f independent assrtment and meisis. 17. Outline hw sexual reprductin leads t even further genetic variatin within a species. 18. Anntate the diagram belw t shw what happens in nn-disjunctin in meisis II. 19. Describe hw nn-disjunctin and fertilisatin lead t trismy. Nn-disjunctin: Fertilisatin: 5
20. Distinguish between nn-disjunctin and trismy. Nn-disjunctin: Trismy: 21. Cmpare the utcmes f nn-disjunctin in anaphase I with anaphase II: Nn-disjunctin in Anaphase I Anaphase II Number f nrmal cells Cells with extra chrmsme (n+1) Cells with chrmsme missing (n-1) 22. Using infrmatin in the graph, utline the effect f maternal age n likelihd f Dwn Syndrme: 23. Describe the effects f Dwn syndrme. 6
24. Cmpare the utcmes f nn-disjunctin in anaphase I with anaphase II: Nn-disjunctin in Anaphase I Anaphase II Number f nrmal cells Cells with extra chrmsme (n+1) Cells with chrmsme missing (n-1) 25. A karytype can be used t test fr nn-disjunctin disrders. Fetal cells are taken and the number f chrmsmes cunted. Outline hw these cells are retrieved: Chrinic Villus Sampling (CVS): Amnicentesis: 26. Describe hw perfrming a nuchal translucency (NT) scan can reduce the number f healthy fetuses terminated as a result f amnicentesis. http://www.guardian.c.uk/sciety/2009/may/16/health-nhs 27. State three visual aspects f hmlgus chrmsmes which can be used t identify them fr the purpse f a karytype? a. Banding patterns b. c. 7
28. Analyze this karytype: Gender: Cnditin: Remember: Meisis is the key t success in Bilgy. If we understand hw meisis wrks and gives rise t genetic variatin, we can understand hw life has evlved and adapted. Make sure yu can explain all f the ways in which meisis leads t variatin amngst a ppulatin. 8